In anaerobic digestion and biogas production, we often hear or read about BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand). Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) are critical parameters used to quantify the organic load of a substrate. This post will explain simply about those two terms.
Category: Terminology
How to Determine Design Pressure
As process engineer dealing with process equipment, we need to determine design pressure. For a vessel, design pressure is called maximum allowable working pressure (MAWP). The MAWP determines the setting pressure of relief valve and must be higher than vessel’s operating pressure. Operating pressure is fixed by process condition.
Table below recommends a minimum differential between operating pressure and MAWP so that the difference between operating pressure and relief valve set pressure provides a sufficient cushion. If the operating pressure is too close to the relief valve setting pressure, small surges in operating pressure could cause the relief valve to activate too soon.
Condensate RVP (Reid Vapor Pressure)
In 2014, I have involved in multi-billion dollars EPC project in Indonesia. The project handled gas and condensate. For condensate, it was stated that the quality shall meet certain RVP (Reid Vapor Pressure) value. In this post, I want to share what RVP is.
Definition of RVP (Reid Vapor Pressure)
Stabilized condensate generally has a vapor pressure specification. Its specification is usually identified by its Reid Vapor Pressure (RVP) or True Vapor Pressure (TVP).
Reid Vapor Pressure (RVP) is related to the vapor pressure of a petroleum product, which measures its inherent tendency to evaporate at 100oF with vapor:liquid ratio of 4:1 (ASTM D323). RVP is a function of hydrocarbon’s composition and is independent of operating temperature and pressure. The value of RVP lies below the true vapor pressure.
The higher the RVP, the more quickly the condensate or oil will vaporize into the air. Read More
Pressure Level in Pressure Vessel Requirement
I am very interested in learning API 520 and API 521 (everything about pressure relieving system). It is because that is the weakest point of me. I want to try make my understanding better, starting from pressure level.
I have heard and read so much about pressure terminology since years ago but still confusing until now. What was the MAWP, MOP, design pressure, set pressure, relieving pressure?
In this post I want to share what I read in API RP 521 (Guide for Pressure Relieving and Depressuring Systems). I read about some terminology in pressure level so that I hope I will not confuse about terms anymore.
Let’s see some terms in column Pressure Vessel Requirement. Read More
Difference between Base Load, Peak Load, and Load Following Power Plant
Yesterday I had a discussion about our current project. The discussion was actually not only limited to that topic, however a topic in general: power plant. When one has plan to build a power plant, he must know operational profile of the power plant. Is it used for base load, peak load, or follower load ? What does it mean?
In this picture I show you the difference between those three. Read More
Understanding Flammability Limit and Explosive Limit
Have you heard about Flammability Limit and Explosive Limit? What does it mean? What the difference? These day I kept wondering if flammability limit and explosive limit is the same? Since I have to check vent stack data sheet from our mechanical engineer, I need to put low flammability limit criteria. What is that?
Explosion occur when three conditions are met:
What is Redwood Viscocity
I just got a really embarassing experience as chemical engineer. Sometimes we deal with a really complicated problem and we can handle that. On the other hand, we handle a simple problem, but we can’t handle that. How if a chemical engineer can not convert the kinematic viscosity expressed in Redwood second into dynamic viscosity? That is my problem. It happened about two days ago. My boss apparently was really disappointed. Read More