Methanol from Biomass — An Option for Switzerland?
The Paul Scherrer Institute has started a project with the goal to demonstrate the production of methanol from a variety of biomass feedstocks such as wood, scrap wood and waste paper. The objective of the project is the full scale demonstration of all aspects of the process - i.e. from the feedstock availability and pretreatment to the utilization of the product methanol in transportation, within this decade. The combination of biomass gasification with water electrolysis using off-peak power will also be studied.
Production costs of liquid fuels from biomass
Abstract There has been considerable interest in producing fuels from biomass and wastes since the oil crises of the last two decades which has been reinforced by subsequent environmental concerns and recent political events in the Middle East. This project was undertaken to provide a consistent and thorough review of the full range of processes for producing liquid fuels from biomass to compare both alternative technologies and processes within those technologies in order to identify the most promising opportunities that deserve closer attention. Thermochemical conversion of wood, straw and refuse includes both indirect liquefaction through gasification, and direct liquefaction through pyrolysis and liquefaction in pressurized solvents. Biochemical conversion is based on a different set of feedstocks that includes wood as well as wheat and sugar beet. Both acid and enzyme hydrolysis are included as options, followed by fermentation. The liquid products considered include gasoline and diesel hydrocarbons that in some cases would require minor refining to convert them into marketable products, and conventional alcohol fuels of methanol and ethanol which have established opportunities for utilization, and fuel alcohol which is as yet unproven in the market place. Results are given both as absolute fuel costs and as a comparison of estimated cost to market price. The results from these two interpretations are quite different. In terms of absolute fuel costs, thermochemical conversion offers the lowest cost products, with the least complex processes generally having an advantage. Exceptions are the unproven direct liquefaction route through zeolites which may be very optimistic, and the Shell middle distillate synthesis process. Biochemical routes are the least attractive. The most attractive processes from comparing production costs to product values are generally the alcohol fuels which enjoy a higher market value. This final analysis should be viewed cautiously since product values are very uncertain and can change significantly over short periods of time, and feedstock prices are also subject to substantial variation with time and location, and this is often the major cost item in the production costs. There is still considerable analysis to be carried out on results from the model, including production cost analyses and sensitivity studies, as well as continued development to improve accuracy and extend the range of technologies considered.
Economics of liquid fuels production by coal gasification
Abstract Since the oil crisis of 1973 considerable interest has been shown in the production of liquid fuels from alternative sources. In particular, processes utilizing coal as the feedstock have received considerable interest. These processes can be divided into indirect liquefaction, direct liquefaction and pyrolysis. This paper describes the modelling of indirect coal liquefaction processes in order to perform a consistent technical and economic assessment of the production of liquid fuels from coal and lignite, using a variety of gasification and synthesis gas conversion technologies. The technologies are modelled on a ‘step model’ basis where a step is defined as a combination of individual unit operations which together perform a significant function on the process streams, such as a methanol synthesis step or gasification and a physical gas cleaning step. Sample results of the modelling are presented to illustrate the scope of the work. These cover a representative range of gasifiers, liquid synthesis processes and products from the large number of combinations of feeds (3 alternatives), gasifiers (10 alternatives), products (6 alternatives), other technical parameters (up to 20 variables) and economic or financial parameters (17 variables), as well as possible sensitivity studies. The results have been validated by major European companies in absolute as well as comparative terms. The main results show that methanol is the most attractive fuel relative to current market prices, followed by fuel alcohol (a mixture of alcohols produced by modified Fischer-Tropsch synthesis), diesel from the Shell middle distillate synthesis process, diesel from the Mobil methanol to olefins gasoline diesel process, gasoline from the same process and finally gasoline from the Mobil methanol to gasoline process. Some products are currently economic based on typical world coal prices. There was a variation in production costs of up to 100% for most products depending on the type of gasifier chosen and specific feedstock.