Chapter 15

Mention the main differences between an oil refinery and a biorefinery.

Set up two process schemes for the production of ethanol from wood, one based on a thermochemical platform and the other based on a biochemical platform. What are advantages and disadvantages of both schemes?

Sometimes, one sees the term "oleochemical-based biorefinery." What is meant by this term and can you give a few examples?

In a biorefinery concept, biomass is pretreated using organosolv so that a cellulose stream is produced that does not dissolve in the organic solvent and is used for paper production; the lignin and hemicellulose parts, though, dissolve and are further separated; the lignin is burned for steam production and the hemicellulose is hydrolyzed to sugars with production of furanic compounds for blending into transportation fuel. Which type of biorefinery is this?

One sometimes uses the production of base chemicals as a useful indicator for the growth of the petrochemical industry. What would you use as indicator for growth in the newly established bio-based economy?

Does crude oil need to be pretreated before entering the atmospheric distillation unit? If so, which pretreatment is required?

A company producing cola wants to increase the production of "green bottles" made of PET (polyethylene terephthalate). Therefore, they plan to build a plant to produce ethylene glycol (one of the two monomers of PET) from sugarcane residues (bagasse). The capacity will be \(500 \mathrm{kt}\).year \({ }^{-1}\). a. Make a block process diagram of how this biorefinery could look like. b. Give the main reactions taking place in the process leading to ethylene glycol. c. How much bagasse (kt.year \(^{-1}\) ) would be needed in this process when bagasse is assumed to consist of \(38 \mathrm{wt} \%\) cellulose \((\mathrm{db}), 27 \mathrm{wt} \%\) hemicellulose, \(20 \mathrm{wt} \%\) lignin, \(3 \mathrm{wt} \%\) proteins, \(9 \mathrm{wt} \%\) extractives (water soluble), and \(3 \mathrm{wt} \%\) ash. Consider ethanol to be an intermediate product, which is only made from the cellulose part via enzymatic hydrolysis and subsequent sugar fermentation. d. Which products can be made from the noncellulosic part of bagasse?

A catalytic cracking unit in an oil refinery produces the so-called amylenes that can be dehydrogenated (abstraction of hydrogen). Which product is formed? Is there a simple biomass-derived process possible to produce the same chemical?

Write out the reaction equations for syngas fermentation to acetic acid with either \(\mathrm{CO}\) or \(\mathrm{CO}_{2}\) as reacting species.

In a process, ethanol is produced from corn using hydrolysis and subsequent fermentation of the starch-derived sugar fraction. The residues are used to feed cattle. a. Which type of biorefinery is this? b. Characterize the complexity using the \(B C I\).

When biomass is pyrolyzed and the bio-oil/char mixture that is produced is fed with heavy oil residues into a fluid catalytic cracker in an oil refinery, is this a biorefinery?

A biorefinery process called "Biofine" has been presented in the recent past (Kamm and Kamm, 2004). It is a biomass-based process route making use of acid hydrolysis and dehydration subprocesses and esterification with ethanol to ethyl levulinate (EL) (an ester of levulinic acid and ethanol). By-products considered are power and formic acid (FA). The production of EL is \(133 \mathrm{kt}\). year \(^{-1}\). The capital cost is 150 million US\$ (consider linear depreciation in 10 years). Table \(15.8\) gives an overview of the prices of the raw materials and by-products. In addition, the water supply costs are US\$ 500,000/year. Regarding labor, there are 17 operators per shift working at a salary of US\$ \(20 / \mathrm{h}\) and two supervisors per shift working at a salary of US\$ \(24 / \mathrm{h}\). Assume an ROI of \(15 \%\). For other costs, take the guidelines given in this chapter (Table 15.6). a. Calculate the cost and return price in US $\$$ per tonne EL produced. b. What is the price in US \$ per GJ HHV? (hint: calculate the heat of combustion of EL). c. Is it possible to produce the required ethanol in the process itself? TABLE 15.8 Overview of costs, yields of by-products, and material amounts for the "Biofine"' process $$ \begin{array}{lll} \text { Raw material/utility/by-product } &{\text { Amount }} & \text { Price in US\$ } \\ \hline \text { Feedstock } & 350 \mathrm{kt} \cdot \mathrm{year}^{-1} & 40 \cdot \mathrm{t}^{-1} \\ \text { Sulfuric acid } & 3.5 \mathrm{kt} \cdot \mathrm{year}^{-1} & 100 \cdot \mathrm{t}^{-1} \\ \text { Caustic soda } & 0.5 \mathrm{kt} \cdot \mathrm{year}^{-1} & 120 \cdot \mathrm{t}^{-1} \\ \text { Ethanol } & 35 \mathrm{kt} \cdot \text { year }^{-1} & 350 \cdot \mathrm{t}^{-1} \\ \text { Hydrogen } & 0.12 \mathrm{kt} \cdot \mathrm{year}^{-1} & 1500 \cdot \mathrm{t}^{-1} \\ \text { Ash disposal } & 17.5 \mathrm{kt} \cdot \mathrm{year}^{-1} & 35 \cdot \mathrm{t}^{-1} \\ \text { Power exported } & 3.1 \mathrm{MW} & 60 \mathrm{MWh}^{-1} \\ \text { Formic acid sold } & 38.5 \mathrm{kt} \cdot \mathrm{year}^{-1} & 110 \cdot \mathrm{t}^{-1} \\ \hline \end{array} $$

Name at least five different pretreatment techniques for biomass by which fractionation of the main biomass contained polvmers can be realized.

Why would lignin valorization to high added value products in newly established modern biorefineries be rather a necessity than just an option?

Gonzalez et al. (2012) report on the cost of different types of equipment in a biorefinery concept for cellulosic ethanol production using gasification. What is the explanation for investment scale factors smaller than one? What is the explanation for scale factors larger than one? In case of a huge scale factor, what would you propose?