# Biosystems Eng.: pasteurization system for peanut butter

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1. Sep 21, 2016

### A Furious Potato

1. The problem statement, all variables and given/known data
In recent years, there have been several significant outbreaks and recalls associated with Salmonella in peanut butter. One company has designed a thermal pasteurization system to reduce pathogen risk in peanut butter, in which the peanut butter is pumped through a heating tube and heated to 85degC (from an initial temperature of 15.6degC). You have been given values for peanut butter density (1,090 kg/m3) and specific heat (1.2 kJ/kgK). If the pasteurizer can deliver 47 kW of heating power, (a) What is the theoretical operating capacity of the pasteurizer (lb/h) of peanut butter? (b) What size storage tank (ft3) is needed to store one shift (8 h) worth of peanut butter for this facility?

2. Relevant equations
V=m/ρ
V=v.ΔT
Q=m.C.ΔT
W=J/s

3. The attempt at a solution
Ok, I'm lost. I don't understand the first question and I don't know where to start. I would appreciate any help.

2. Sep 21, 2016

### Nidum

Deleted

Last edited: Sep 21, 2016
3. Sep 21, 2016

### Staff: Mentor

Why don't you start by determining how many kg of peanut butter can pasteurized in an 8-hour shift? You can always convert that to pounds afterward.

Things associated with answering that question:
- What is the available Q over an 8-hour shift?
- What is the ΔT required?

4. Sep 21, 2016

### rachelmarie

Hi I'm in the same class and don't know the answer either did you figure it out?