Torrefaction is considered to be a pre-treatment technology to make biomass more suitable for co-firing applications. Especially, the improved grindability of biomass after torrefaction may enable higher co-firing rates in the near future. Torrefaction is, however, a technology that is not commercially available yet. This work contributed to the development of torrefaction by means of extensive parametric research, process simulations and process design. Experimental work has revealed that torrefied biomass can be produced with a grindability comparable to coal and with a combustion reactivity comparable to wood. The process can be operated at high process energy efficiency; typically 96% thermal efficiency and 92% net process efficiency (including the internal electricity consumption). Reactor technology based on moving-bed principles is identified very promising reactor for torrefaction. A production plant of 60-kton/a product requires a capital investment of 5.2 to 6.3 Meuro. The total production costs amount in the range of 40 to 56 euro/ton product (excluding feedstock costs), which is 2 to 2.8 euro/GJ. It is recommended to further develop moving-bed technology for torrefaction by means of pilot-scale testing (prototype) and to investigate other important product properties such as hydrophobic nature and leeching behaviour in relation to operating conditions.

Torrefaction for biomass co-firing in existing coal-fired power stations BIOCOAL

https://www.ou.edu/class/che-design/pub-papers/A%20review%20of%20recent%20design%20procedures%20for%20water%20networks%20in%20refineries%20and%20process%20plants(Bagajewicz)-00.pdf

A review of recent design procedures for water networks in refineries and process plants

CO2 capture by hydrate crystallization – A potential solution for gas emission of steelmaking industry

This article presents results from experimental studies and techno-economic analysis of a catalytic process for the conversion of whole biomass into drop-in aviation fuels with maximal carbon yields. The combined research areas highlighted include biomass pretreatment, carbohydrate hydrolysis and dehydration, and catalytic upgrading of platform chemicals. The technology centers on first producing furfural and levulinic acid from five- and six-carbon sugars present in hardwoods and subsequently upgrading these two platforms into a mixture of branched, linear, and cyclic alkanes of molecular weight ranges appropriate for use in the aviation sector. Maximum selectivities observed in laboratory studies suggest that, with efficient interstage separations and product recovery, hemicellulose sugars can be incorporated into aviation fuels at roughly 80% carbon yield, while carbon yields to aviation fuels from cellulose-based sugars are on the order of 50%. The use of lignocellulose-derived feedstocks rather than commercially sourced model compounds in process integration provided important insights into the effects of impurity carryover and additionally highlights the need for stable catalytic materials for aqueous phase processing, efficient interstage separations, and intensified processing strategies. In its current state, the proposed technology is expected to deliver jet fuel-range liquid hydrocarbons for a minimum selling price of $4.75 per gallon assuming nth commercial plant that produces 38 million gallons liquid fuels per year with a net present value of the 20 year biorefinery set to zero. Future improvements in this technology, including replacing precious metal catalysts by base metal catalysts and improving the recyclability of water streams, can reduce this cost to $2.88 per gallon.

Production of renewable jet fuel range alkanes and commodity chemicals from integrated catalytic processing of biomass

In this paper we present a new process to produce furfural and co-products of formic and acetic acids from waste aqueous hemicellulose solutions using a continuous two zone biphasic reactor. We estimate this approach uses 67% to 80% less energy than the current industrial processes to produce furfural. An economic analysis indicates that furfural can be produced with this process at 366 US$ per metric ton which is 25% of the selling price of furfural in the U.S. market today. This analysis assumes a plant capacity of 78 kiloton per year of furfural, 12 kiloton per year of formic acid and 44 kiloton per year of acetic acid (processing 160 ton per hour of hemicellulose solutions with a xylose concentration of 10.7 wt%) and is based on the data collected in this paper. Formic acid and acetic acid are probably produced from the acid hydrolysis of formylated and acetylated xylose oligomers, respectively. Furfural is produced in a two-step process consisting of the hydrolysis of xylose oligomers followed by the dehydration of xylose monomers and then extraction of the furfural into an organic solvent. Two types of hemicellulose solutions were used as the feedstock including a hot water extract and a green liquor extract derived from Northeastern hardwood trees. The hemicellulose solution contains mainly xylose oligomers as well as glucose, arabinose, lactic acid, acetic acid, formic acid, and other minor products. We found that the reaction temperature, the space velocity, the volumetric organic to aqueous phase ratio, and the acid concentration have significant effects on the furfural production. Under the optimized condition, a furfural yield of 90% can be achieved in the reactor from the hot water extract containing 10.7 wt% xylose. A conceptual design is performed for the integration of the production of furfural, formic and acetic acids, the liquid–liquid split, and subsequent three-stage distillations. We demonstrate that high purity (>99%) of furfural, formic and acetic acids can be obtained, with a final recovery of more than 97%, 56%, and 88% of the furfural, formic acid and acetic acid, respectively.

/pdf/production-of-furfural-and-carboxylic-acids-from-waste-3xrpww5jdp.pdf

Production of furfural and carboxylic acids from waste aqueous hemicellulose solutions from the pulp and paper and cellulosic ethanol industries

Part I A Strategy For Process Synthesis and Analysis1 The Nature of Process Synthesis and Analysis2 Engineering Economics3 Economic Decision Making-Design of a Solvent Recovery SystemPart II Developing A Conceptual Design and Finding the Best Flowsheet4 Input Information and Batch vs Continuous5 Input-Output Structure of the Flowsheet6 Recycle Structure of the Flowsheet7 Separation System8 Heat-Exchanger Networks9 Cost Diagrams and the Quick Screening of Process AlternativesPart III Other Design Tools And Applications10 Preliminary Process Optimization11 Process Retrofits12 Computer-Aided Design Programs13 Summary of the Conceptual Design Procedure and Extensions of the MethodAppendixes

James M. Douglas

Papers

Conceptual Design of Chemical Processes