| 1. |
- Aebersold, Ruedi, et al.
(författare)
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How many human proteoforms are there?
- 2018
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Ingår i: Nature Chemical Biology. - : NATURE PUBLISHING GROUP. - 1552-4450 .- 1552-4469. ; 14:3, s. 206-214
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Tidskriftsartikel (refereegranskat)abstract
- Despite decades of accumulated knowledge about proteins and their post-translational modifications (PTMs), numerous questions remain regarding their molecular composition and biological function. One of the most fundamental queries is the extent to which the combinations of DNA-, RNA-and PTM-level variations explode the complexity of the human proteome. Here, we outline what we know from current databases and measurement strategies including mass spectrometry-based proteomics. In doing so, we examine prevailing notions about the number of modifications displayed on human proteins and how they combine to generate the protein diversity underlying health and disease. We frame central issues regarding determination of protein-level variation and PTMs, including some paradoxes present in the field today. We use this framework to assess existing data and to ask the question, "How many distinct primary structures of proteins (proteoforms) are created from the 20,300 human genes?" We also explore prospects for improving measurements to better regularize protein-level biology and efficiently associate PTMs to function and phenotype.
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| 2. |
- Agar, David, et al.
(författare)
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A systematic study of ring-die pellet production from forest and agricultural biomass
- 2018
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Ingår i: Fuel Processing Technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 180, s. 47-55
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Tidskriftsartikel (refereegranskat)abstract
- Continuous global growth in the pellet production industry and renewable energy policy targets have driven interest in under-utilised lignocellulosic biomass. In this comprehensive study, pelleting trials were systematically carried out using a pilot-scale ring-die pellet press with eight different biomass feedstock; logging residues, pine bark, wheat straw, reed canary grass, coppiced willow, poplar and beech. A standard spruce/pine sawdust blend was pelleted as a reference material.Pellets were produced from feedstock at four different moisture content levels, through two press channel lengths and three replicate steady-state sampling periods. A total of 192 batches of 8 mm diameter pellets were produced within a press channel length and moisture content range of 30-60 mm and 9-17% respectively. Pellet production had a range of 141-206 kg h(-1) and relatively good pellet quality was achieved for a majority of the studied feedstock. The best pellet batches had a mechanical durability and bulk density range of 91-99% and 532-714 kg m(-3) respectively, corresponding to an energy density range of 8.3-12.5 GJ m(-3) (as received). The extruded pellet temperature ranged between 99 and 131 degrees C and was correlated to pellet bulk density for hardwoods, pine bark and forest residues. The normalised energy (reference value of 1) used in pelleting all materials varied between 0.76 and 1.3 being highest for the hardwoods and lowest for straw and forest residues.
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| 3. |
- Agar, David, et al.
(författare)
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Combining behavioural TOPSIS and six multi-criteria weighting methods to rank biomass fuel pellets for energy use in Sweden
- 2023
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Ingår i: Energy Reports. - 2352-4847. ; 10, s. 706-718
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Tidskriftsartikel (refereegranskat)abstract
- EU energy and climate policies continue to drive interest in biomass fuel pellets which can be produced from a wide variety of feedstock. The use of multi-criteria decision analysis (MCDA) to support feedstock selection has the potential for more transparent and better decision-making. This study applies the behavioural TOPSIS, a prominent MCDA technique, to rank pellets for energy use in Sweden produced from under-utilised forest and agricultural biomass. Seven criteria were used to assess and rank the biomass pellets. The alternatives include 88 types of pellets from 11 biomass materials. Possible attitudes of an expert towards the risk of losses (risk averse, risk neutral and risk-seeking) were combined with six sets of criteria weights obtained using six weighting methods – a total of 18 input settings (scenarios). Despite having different input settings, almost identical results were obtained in all scenarios, meaning that the rankings were stable and consistent. Across all 18 scenarios, pellets produced from a reference spruce/pine sawdust blend are ranked ahead of other pellet types. Pellets produced from Scots pine bark exhibited stable and consistent rankings across all scenarios; and thus this biomass is the second-best overall. The next best materials overall are poplar, reed canary grass and wheat straw, whereas torrefied pellets (torrefied beech, poplar and wheat straw) were ranked last in all scenarios. Combining behavioural TOPSIS and a variety of criteria-weighting methods is a meaningful way of improving decision-making with respect to producing a more valid and reliable ranking of biomass fuel pellets for energy use in Sweden.
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| 4. |
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| 5. |
- Agar, David
(författare)
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Distribution of ash forming elements during pyrolysis of municipal wastewater sludge and sludge from milk processing factories
- 2018
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Konferensbidrag (refereegranskat)abstract
- In the long term, there is a need for alternative methods to recover energy and nutrients from increasing volumes of sludge generated from wastewater treatment plants. Pyrolysis can be an interesting option, which can reduce health and environmental risks, while providing an avenue for the recovery of energy and nutrients. One of the main concerns related to thermal conversion technologies is the release and fate of heavy metals and contaminants existing in the feedstock. Therefore, a detailed understanding of the transformation pathways of problematic compounds is necessary to assess the suitability of pyrolysis. In this study pyrolysis of dried dairy sludge and sewage sludge was carried out using a simple laboratory fixed bed reactor. Characterisation of the feedstock and pyrolysis products was performed through proximate and ultimate analysis and the content of major and minor ash forming elements were determined. The mass balance information obtained from the experimental tests was used for an indicative distribution of Al, Ca, Fe, K, Mg, Na, P, S, Si, As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Se, Ti, V and Zn between solid and liquid pyrolysis products. Results indicate that distribution of major elements between pyrolysis products was similar for dairy sludge and sewage sludge, with Ca, Mg, Fe, P, Si, Al, Na and K predominantly retained in pyrolysis chars (pyrogenic solids). However, substantial quantities of Al, K, Na and Si were detected in pyrolysis oil and in the aqueous fraction. The heavy metals and trace elements were mainly retained in the pyrolysis chars (pyrogenic solids) with the exception of As, Ba, Cd, Se, Sb and Pb, which were also detected in the liquid products.
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| 6. |
- Agar, David
(författare)
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Energy recovery through co-pyrolysis of wastewater sludge and forest residues -The transition from laboratory to pilot scale
- 2021
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 158
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Tidskriftsartikel (refereegranskat)abstract
- Anaerobically digested sewage sludge mixed with forest residues was pyrolysed at 800 °C, at laboratory and pilot scale. The study quantified differences in char and gas yields for tests carried out in a simple fixed bed laboratory reactor and rotating retort pyrolyser at pilot scale, when the residence time of feedstock was 10 min in both cases. The yield of char from pilot scale was 4 % lower than from laboratory scale while the yield of gas was 15.7 % higher. During the pilot scale pyrolysis of anaerobically digested sewage sludge blended with forest residues the gas quality for energy recovery applications was assessed and the fate of impurities (tar, NH3 and H2S) was investigated. The raw pyrolysis gas contained 14.6 g/Nm3 of tar, 36.9 g/Nm3 of NH3 and 793 ppm of H2S. Sixteen N-containing tar species were identified of which pyridine, propenenitrile, 2-methyl-, benzonitrile, and indole are found to be the most abundant. The yield of N-containing tar compounds accounted for approx. 12 % of total tar content. Conditioned pyrolysis gas contained 7.1 g/Nm3 of tar, 0.036 g/Nm3 of NH3 and 119 ppm of H2S. Benzene was by far the most abundant tar compound followed by toluene and styrene. The specifications of the used internal combustion engine were exceeded due to the sum of tar compounds such as fluorantrene and pyrene with 4+ aromatic rings (at 0.0015 g/Nm3) and NH3 content The effectiveness and sustainability of energy recovery in wastewater treatment can be improved using forest industry by-products.
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| 7. |
- Agar, David, et al.
(författare)
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Pelleting torrefied biomass at pilot-scale – Quality and implications for co-firing
- 2021
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Ingår i: Renewable Energy. - : Elsevier BV. - 0960-1481. ; 178, s. 766-774
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Tidskriftsartikel (refereegranskat)abstract
- The co-firing of solid biofuels in coal plants is an attractive and fast-track means of cutting emissions but its potential is linked to biomass densification. For torrefied materials this topic is under-represented in literature. This pilot-scale (121–203 kg h−1) pelleting study generated detailed knowledge on the densification of torrefied biomass compared to untreated biomass. Four feedstock with high supply availability (beech, poplar, wheat straw and corn cob) were studied in their untreated and torrefied forms. Systematic methods were used to produce 180 batches of 8 mm dia. pellets using press channel length (PCL) and moisture content (MC) ranges of 30–60 mm and 7.3–16.6% (wet basis) respectively. Analysis showed that moderate degrees of torrefaction (250–280 °C, 20–75 min) strongly affected pelleting behaviour. The highest quality black pellets had a mechanical durability and bulk density range of 87.5–98.7% and 662–697 kg m−3 respectively. Pelleting energy using torrefied feedstock varied from −15 to +53 kWh t−1 from untreated with increases in production fines. Optimal pelleting MC and PCL were reduced significantly for torrefied feedstock and pellet quality was characterised by a decrease in mechanical durability and an increase in bulk density. Energy densities of 11.9–13.2 GJ m−3 (as received) were obtained.
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| 8. |
- Agar, David
(författare)
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Pyrolysis of wastewater sludge and composted organic fines from municipal solid waste: laboratory reactor characterisation and product distribution
- 2018
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 25, s. 35874-35882
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Tidskriftsartikel (refereegranskat)abstract
- Sludge from municipal wastewater treatment plants and organic fines from mechanical sorting of municipal solid waste (MSW) are two common widespread waste streams that are becoming increasingly difficult to utilise. Changing perceptions of risk in food production has limited the appeal of sludge use on agricultural land, and outlets via landfilling are diminishing rapidly. These factors have led to interest in thermal conversion technologies whose aim is to recover energy and nutrients from waste while reducing health and environmental risks associated with material re-use. Pyrolysis yields three output products: solid char, liquid oils and gas. Their relative distribution depends on process parameters which can be somewhat optimised depending on the end use of product. The potential of pyrolysis for the conversion of wastewater sludge (SS) and organic fines of MSW (OF) to a combustion gas and a carbon-rich char has been investigated. Pyrolysis of SS and OF was done using a laboratory fixed-bed reactor. Herein, the physical characterisation of the reactor is described, and results on pyrolysis yields are presented. Feedstock and chars have been characterised using standard laboratory methods, and the composition of pyrolysis gases was analysed using micro gas chromatography. Product distribution (char/liquid/gas) from the pyrolysis of sewage sludge and composted MSW fines at 700 degrees C for 10min were 45/26/29 and 53/14/33%, respectively. The combustible fractions of pyrolysis gases range from 36 to 54% for SS feedstock and 62 to 72% from OF. The corresponding lower heating value range of sampled gases were 11.8-19.1 and 18.2-21.0MJm(-3), respectively.
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| 10. |
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